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Bacterial removal of nitrate, nitrite and sulphate in wastewater
PII: S0043-1354(98)00069-4
Wat. Res. Vol. 32, No. 10, pp. 3080±3084, 1998 # 1998 Elsevier Science Ltd. All rights reserved Printed in Great Britain 0043-1354/98 $19.00 + 0.00
BACTERIAL REMOVAL OF NITRATE, NITRITE AND SULPHATE IN WASTEWATER R. M. AWADALLAH*, M. E. SOLTAN, M. S. A. SHABEB and S. M. N. MOALLA Department of Chemistry, Faculty of Science, Aswan, Egypt (First received May 1994; accepted in revised form February 1998) ÿ 2ÿ AbstractÐSolutions of various concentrations of NOÿ 2 , NO3 or SO4 , and equal concentrations of ÿ ÿ ÿ ÿ 2ÿ NO2 +NO3 and NO2 +NO3 +SO4 in thrice distilled water as well as in samples of industrial wastewater euents of Kima company (a factory producing ammonium nitrate coated with limestone powder fertilizer) at Aswan City and River Nile water collected from Mansoura, Damietta, Kafr El Zayat and Ed®na were tested against Bacillus Stearothermophilus Asw 88 and Bacillus Stearothermophilus Asw 129 and autoclaved at 37 and 508C for various hours using nutrient yeast extract (NYE) medium. ÿ 2ÿ Detection and assay of NOÿ 2 , NO3 and SO4 in simple salt solutions using NaNO2, NaNO3, Na2SO4 and H2SO4 after screening for 120 h indicates complete depletion of these components as they are good and convenient essential nutrient sources for both strains utilized safely for the treatment of polluted water. The strains are not pathogenic and they have no hazardous eect on human and animal life. The method is ecient and the results of the analysed water samples are consistent with the permissible safety baseline levels desired for domestic, irrigation and industrial purposes and also for drinking purposes after disinfection according to the World Health Organisation Standards. Complete depletion of ÿ ÿ ÿ SO2ÿ 4 after 96 h, NO2 and NO3 after 144 h, COD after 168 h and 23±30% degradation of Cl after 168 h, are obtained.The biological treatment of industrial wastewater euents of Kima Company and ÿ 2ÿ River Nile water at Damietta, Mansoura, Ed®na, and Kafr El Zayat containing NOÿ 2 , NO3 , SO4 , ÿ HCOÿ 3 , Cl and COD (organic matter) shows a progressive biodegradation of nutrients' levels with ÿ 2ÿ time, reaching complete depletion (NOÿ 2 , NO3 , SO4 and COD) due to the degradation eect by nitrogen and sulphur reducing bacteria. The decrease or absence (depletion) of nutrients and other parameters' levels may be related to their consumption by bacterial biomass. # 1998 Elsevier Science Ltd. All rights reserved
Key wordsÐindustrial wastewater euents, biodegradation, treatment, bacteriological, depletion, bacteria, strains, microorganisms, Kima, Company, drain INTRODUCTION
In Upper Egypt and in the Delta, many cities and industrial complexes are sited on the two banks of the River Nile in order to meet the increasing demands of water for domestic, agricultural and industrial use and for various other purposes. But some industrial establishments drain their euents directly into the River Nile, particularly those constructed on Damietta and Rosetta branches and pollute the essential source of water at Damietta, Mansoura, Kafr El Zayat and Ed®na. Many eorts and methods have been applied to treat polluted water in order to utilize the treated water in domestic use for cattle feeding and even for irrigation, because nitrite, nitrate, sulphate, organic compounds (chemical oxygen demand, COD; biochemical oxygen demand, BOD) and total hardness (TH) play a central role in the pollution of water and adversely aect the quality of water, these eects being re¯ected on biota (®sh, animal and human life). Therefore, the contribution of bacteria to the degradation of pollutants and contaminants may be *Author to whom all correspondence should be addressed.
considerable. Nevertheless the biological processes are not fully understood, and basic research is still necessary. The chemical compositions of the High Dam Lake, River Nile and Kima drain (at Aswan City, Egypt) water have been studied and characterized by many authors (Awadallah, 1984; Awadallah et al., 1993; El Dardir, 1984; Fritze et al., 1990; Sherif et al., 1978; Sneath et al., 1986). The purpose of the present work is targeted at introducing Bacillus Stearothermophilus Asw 88 and Bacillus Stearothermophilus Asw 129 as sulphur and nitrogen reducing bacterial species for the removing of ÿ 2ÿ NOÿ 2 , NO3 or SO4 as individuals or in binary and ternary admixtures in simple salts as well as applying these microorganisms for the biodegradation of ÿ 2ÿ ÿ ÿ NOÿ 3 , NO3 or SO4 , Cl , HCO3 and COD pollutants existing in industrial wastewater and in polluted Nile water.
MATERIALS AND METHODS
Chemicals All chemicals used were purchased from BDH, Aldrich, Sigma, Riedel de HaeÈn and Merck (A.R., 99.9%).
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ÿ 2ÿ Bacterial removal of NOÿ 2 , NO3 and SO4
Preparation of standard solutions Stock nitrite, nitrate and sulphate solutions were prepared by dissolving the appropriate amounts of NaNO2, NaNO3 and Na2SO4 and diluting with an appropriate volume of concentrated H2SO4 (A.R.,98%, sp.gr., 1.835 g/ cm3) in thrice distilled water. Appropriate dilute solutions of 1, 2, 3, 5, 10, 50, 100, 150, 200, 250 and 300 mg NOÿ 2 or NOÿ 3 /l and 5, 10, 50, 100, 200, 300, 400 and 500 mg SO2ÿ 4 /l (from Na2SO4 and H2SO4) were prepared by appropriate dilution from stock standard solutions (Merck, 1980). Isolation of microorganisms The alkalophilic strains, Bacillus Stearothermophilus Asw 88 and Bacillus Stearothermophilus Asw 129 were isolated from Aswan soil (Shabeb, 1995) and identi®ed according to recommended procedures (Sneath et al., 1986; DEWAS, 1980; Fritze et al., 1990; Horikoshi and Akiba, 1980). Preparation of the bacterial suspension (5) The original agar medium was given by Bunt and Rovira, and prepared by dissolving 0.5 g peptone, 0.3 g yeast extract and 0.5 g NaCl in 100 deionized water. The medium was sterilized at 1218C for 15 min and pH was adjusted to 10.5.
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was evaporated till dryness. The residue was allowed to cool, then concentrated sulphuric acid was added, followed by the addition of tridistilled water, 30% NaOH and 2.5 N NaOH. Bacterial suspension was added at the same concentration in the treated water samples. A yellow colour appeared. Absorbance of the solution was measured against a blank solution at l = 420 nm. An ÿ absorbance±concentration graph of NOÿ 2 or NO3 was constructed. In the case of the determination of sulphate, a turbidimetric method (Merck, 1980; Vogel, 1982) was applied using NaCl/HCl±glycerol±ethanol reagent and BaCl2 crystals (20±30 mesh). Transmittance (turbidity) was measured at l = 420 nm against a blank solution containing the same constituents (and bacterial suspension) except sulphate. A transmittance±concentration graph was ÿ constructed. In addition, HCOÿ in the 3 , COD and Cl industrial wastewater and in the River Nile water samples, under study, were assayed using recommended methods (APHA, 1980; Sherif et al., 1978, 1980). However, before biological treatment, Kima industrial wastewater and the surface River Nile water samples collected from Damietta, Mansoura, Kafr El Zayat and Ed®na were analysed for 2ÿ 2ÿ ÿ 2+ pH, O, free CO2, HCOÿ , Mg2+, 3 , CO3 , SO4 , OH , Ca ÿ ÿ 3ÿ , NO , NO , PO , Fe, Al, SS, DS and TH, Clÿ, SO2ÿ 4 2 3 4 COD using recommended methods (APHA, 1980; Sherif et al., 1978; Sherif et al., 1980).
Water samples collection Water samples were obtained from the washings of fertilizer tower wastes, fertilizer plant wastes (wastes No. 1 and 2), condensate basin, washing ¯oor waste, acid plant wastes basin, cooling towers basin, basin of ®nal collection (collection basins' wastes No. 1 and 2) inside the grounds of Kima Company for Chemical Industries and from the pipe of ®nal euents (®nal drain) into Kima drain shaft at Aswan, and from River Nile water at Damietta, Mansoura, Kafr El Zayat and Ed®na. The water samples were kept in ampered glass bottles. Working procedure Various concentrations of nitrite and nitrate from NaNO2 and NaNO3 (1, 2, 3, 5, 10, 50, 100, 200 mg/l), sulphate from both and Na2SO4 and H2SO4 (50, 100, 200, ÿ 300, 400, 500 mg/l), equal concentrations of NOÿ 2 +NO3 (5 + 5, 10 + 10, 50 + 50, 100 + 100, 150 + 150, 200 + 200, 250 + 250, 300 + 300 mg/l) and ÿ 2ÿ NOÿ (50 + 50 + 50, 100 + 100 + 100, 2 +NO3 +SO4 200 + 200 + 200, 300 + 300 + 300 mg/l) in 100 ml sterilized water, 100 ml of polluted water samples collected from Kima Company (washing basin of fertilizer tower wastes, condensate basin, washing ¯oor wastes basin, acid plant wastes basin, cooling towers basin, basin of ®nal collection (No. 1 and 2), 100 ml from the pipe of ®nal euents drained into Kima drain shaft and 100 ml of River Nile water taken from the surface at Damietta, Mansoura, Kafr El Zayat and Ed®na were inserted into sterilized 250 ml pyrex glass bottles and 1 ml of bacterial suspension was added to all bottles. The bottles were stoppered and incubated at 37 and 508C (the strains are facultative alkalophilic bacteria) for 24, 48, 72, 96, 120, 144 and 168 h. After incubation, the reference solutions and polluted ÿ 2ÿ water samples were analysed for NOÿ 2 , NO3 and SO4 . NOÿ 2 was determined using the modi®ed Griess±Ilosvay method (APHA, 1980). In this method, dilute sulphanilic acid and a-naphthylamine solutions were acted upon by nitrous acid, a red colouration produced which might be used for the spectrophotometric determination of nitrite against a blank (containing the same reagents and the culture media) and measuring the absorbance at l = 250 nm. NOÿ 3 was estimated applying the sodium salicylate method (DEWAS, 1980). In this method, sodium silicate was added to 50 ml of a ®ltered water sample and the solution
RESULTS AND DISCUSSION
The results of the eect of Bacillus Stearothermophilus Asw 88 and Bacillus ÿ Stearothermophilus Asw 129 on NOÿ , NO 2 3 and 2ÿ SO4 as individuals or in admixtures (binary, ÿ ÿ ÿ 2ÿ NOÿ 2 +NO3 and ternary, NO2 , NO3 +SO4 ) after biological treatment for 24, 48, 72, 96, 120, 144 and 168 h are represented in Figs 1 and 2. The results of physicochemical parameters of the water samples collected from Kima Company and Kima drain shaft at Aswan and those collected from the River Nile at Damietta, Mansoura, Ed®na and Kafr El Zayat show very high values of conductivity of Kima Company and Kima drain waters, and Nile water at Damietta. In addition, wastewaters of fertilizer plant waste pits No. 1 and 2, condensate basin and basin of washing ¯oor waste at Kima Company and Nile water at Damietta exhibit terriÿ 2+ ble ®gures of CO2ÿ , Mg2+, TH, Clÿ 3 , OH , (Ca 2ÿ ÿ and SO4 at Damietta), NO2 , NOÿ 3 , SS, DS and ÿ COD. Table 1 shows the results of NOÿ 2 , NO3 , 2ÿ ÿ ÿ SO4 , HCO3 , Cl and COD in the collected samples after biological treatment with the strains under study for 24, 48, 72, 96, 120, 144 and 168 h. The results show a progressive decrease of NOÿ 2, 2ÿ NOÿ 3 and SO4 concentrations (as individuals and in admixtures as present in pure salts) with treatÿ ment time. However, 1, 2 and 3 mg NOÿ 2 or NO3 /l are completely depleted (100% degradation) after ÿ 24 h, 5 and 10 mg NOÿ 2 or NO3 /l are completely depleted after 48 h, 50 mg NOÿ 2 /l is completely depleted after 72 h, 100 and 200 mg NOÿ 2 /l are completely depleted after 96 h, while 50, 100 and 200 mg NOÿ 2 /l are completely depleted after 120 h treatment. Mixtures of 5 + 5 and 10 + 10 and 50 + 50, 100 + 100, 150 + 150, 200 + 200,
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R. M. Awadallah et al.
Fig. 1. Removal of nitrite (A), nitrate (B) and sulphate (C) from a mixture of equal amounts of them by B. stearothermophilus Asw 129 and Asw 88. ÿ 250 + 250 and 300 + 300 mg/l of NOÿ 2 +NO3 are completely depleted after 48 and 120 h. Also, 50 mg SO2ÿ 4 /l (from Na2SO4 or H2SO4) are completely desin admixtures tructed after 72 h. However, SO2ÿ 4 (pure salts) are completely depleted after 48 h in the ÿ 2ÿ case of 50 mg NOÿ 2 +50 mg NO3 +50 mg SO4 (in Na2SO4 or H2SO4)/l and 120 h in the case of the other concentrations. In the polluted samples, NOÿ 2, 2ÿ NOÿ 3 and SO4 in the condensate basin (pH 10.96; NOÿ 3 , 350 mg/l) are completely depleted after 48 h. However, NOÿ 2 in washing ¯oor basin (23 mg/l), acid plant (0.15 mg/l) wastes basin, Damietta, Kafr El Zayat and Ed®na water is completely depleted after 48 h. NOÿ in collection basin No. 1, 3
Damietta, Mansoura, Kafr El Zayat and in Ed®na exhibits is completely depleted after 48 h. SO2ÿ 4 complete degradation in the condensate basin after 24 h, in washing ¯oor, acid plant, collection basins' wastes No. 1 and 2, and ®nal drain waste after 72 h and in cooling towers waste, Damietta, Mansoura, Kafr El Zayat and Ed®na after 96 h. COD has completely disappeared after 24 (condensate basin and acid plant wastes), 72 (Damietta), 96 (washing ¯oor wastes, Mansoura, Kafr El Zayat and Ed®na), 144 (collection basin No. 1, Clÿ, 103.2; SO2ÿ 4 , 85; ÿ NOÿ 2 , 117; NO3 , 360 mg/l) and 168 h (fertilizer ÿ plants' wastes No. 1 (NOÿ 2 , 110; NO3 , 530 mg/l) ÿ ÿ and 2 (NO2 , 111; NO3 , 310 mg/l) and collection
Fig. 2. Removal rates of nitrite and nitrate were almost the same irrespective of individual and in mixed solutions.
48
72
96
120
144
NOÿ 2 (mg/l) NOÿ 3 (mg/l) SO2ÿ 4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
NOÿ 2 (mg/l) NOÿ 3 (mg/l) SO2ÿ 4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
NOÿ 2 (mg/l) NOÿ 3 (mg/l) SO2ÿ 4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
NOÿ 2 (mg/l) NOÿ 3 (mg/l) SO2ÿ 4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
NOÿ 2 (mg/l) NOÿ 3 (mg/l) 2ÿ SO4 (mg/l) HCOÿ 3 (mg/l) ÿ
0.0 0.0 0.0 35.1 25.9 0.0
0.0 0.0 0.0 38.2 27.3 1.2
0.0 0.03 0.0 42.1 28.7 7.2
0.0 0.12 0.0 44.1 29.9 13.1
0.15 2.1 2.3 48.2 31.2 25.2
1.68 9.87 6.82 51.9 34.8 33.2
5.5 17.75 17.35 60 36.6 57.3
110 530 82 0.0 46.45 75.6
1
0.0 0.0 0.0 28.1 29.0 0.0
0.0 0.0 0.0 28.4 29.2 0.7
0.05 0.12 0.0 29.6 30.5 3.4
0.23 0.88 0.0 32.6 31.2 6.5
0.45 2.3 0.13 5.2 5.2 14.0
10.2 11.02 4.9 53.2 36.4 29.6
17.25 20.75 12.25 62 39.2 42.4
111 310 78 0.0 54.19 68
2
0.0 0.0 0.0 27.7 169 0.0
0.0 0.0 0.0 27.9 172 0.0
0.0 0.0 0.0 29.0 189 0.0
0.0 0.0 0.0 31.0 195 0.0
0.0 0.0 0.0 35 200.1 0.0
0.0 0.0 0.0 38 225 0.0
1.4 202.2 0.0 40 250 0.0
0.3 330 0.0 0.0 309.7 2.8
3
0.0 0.0 0.0 30.9 12.9 0.0
0.0 0.0 0.0 31.0 13.8 0.0
0.0 5.3 0.0 31.2 14.3 0.0
0.0 18.4 0.0 33.1 15.9 0.0
0.0 55.3 0.0 36 16.2 0.6
0.0 110 4.51 42.0 18.3 5.2
1.9 205 9.72 46 21.5 14.9
23 800 61 0.0 33.55 18.4
4
0.0 0.0 0.0 99.5 13.5 0.0
0.0 0.0 0.0 99.8 14.2 0.0
0.0 0.0 0.0 102 15.1 0.0
0.0 0.0 0.0 109 16.2 0.0
0.0 0.0 0.0 118 17.3 0.0
0.0 20 3.92 145.0 19.8 0.0
0.08 0.0 8.61 49.7 24.9 0.0
0.15 5.0 52 168 30.97 18.4
5
0.0 0.0 0.0 100.4 20.4 0.2
0.0 0.0 0.0 101 21.2 2.9
0.0 0.12 0.0 105 23.9 12.1
0.0 3.1 0.0 111 25.1 23.6
0.0 9.3 0.1 122 29.2 65.1
0.05 22.2 5.61 152.0 33.2 98
1.2 45.5 16.65 161.3 37.9 147
(A) 78 335 99 168 41.29 162.8
6
8
9
At 0 h (before treatment) 117 119 109 360 380 200 85 93 90 0.0 0.0 0.0 103.2 206.5 141.9 74.4 90 86.8 (B) After 24 h 4.05 4.5 18.75 2.25 11.22 25.75 13.1 15.85 14.78 90.6 47.9 43.4 89.6 187.5 126.3 59.7 74.9 69.8 (C) After 48 h 0.92 1.10 3.7 0.0 5.4 9.2 5.3 4.81 4.21 89.0 45.2 43.0 75.3 178.3 117.3 4.2 35.4 45.2 (D) After 72 h 0.05 0.15 0.32 0.0 1.2 2.7 0.0 0.0 0.0 82 41 39 68.9 159.4 110.2 13.2 25.6 29.1 (E) After 96 h 0.0 0.0 0.05 0.0 0.06 0.12 0.0 0.0 0.0 79.0 37.0 36.0 61.1 149.2 103 2.5 9.2 12.5 (F) After 120 h 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 77 36 34.9 59.4 139.2 98.2 0.5 1.4 0.0 (G) After 144 h 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 58.3 38.1 97.5 49.5 129.2 95.4 0.0 0.2 0.4 (H) After 168 h 0.0 0.0 0.0 0.0 0.0 0.0 0.0 .0 0.0 58.0 37.8 97.2 47.2 126.5 93.3 0.0 0.0 0.0
7
11
0.0 0.0 0.0 12.8 11.2 0.0
0.0 0.0 0.0 12.9 11.5 0.0
0.0 0.0 0.0 115 13.1 0.0
0.0 0.0 0.0 121 15.3 0.0
0.0 0.0 0.35 125 16.4 0.0
0.0 0.0 7.55 139.0 18.2 0.2
0.16 0.02 20 140 23.9 2.1
0.0 0.0 0.0 1243 14022 0.0
0.0 0.0 0.0 1287 14081 0.0
0.0 0.0 0.0 1301 14211 0.0
0.0 0.0 0.0 1381 14613 0.0
0.0 0.0 3.4 1415 14909 0.2
0.05 0.0 25.1 1690 15311 2.1
0.12 0.0 60 1710 17210 5.3
0.212 3.18 0.172 0.022 25.1 172 150 1750 23.4 18401 3.6 8.3
10
0.0 0.0 0.0 113 13.1 0.0
0.0 0.0 0.0 114 13.9 0.0
0.0 0.0 0.0 116 15.1 0.0
0.0 0.0 0.0 121 16.2 0.0
0.0 0.0 1.1 133 17.2 0.1
0.0 0.0 9.9 150 19 1.2
0.19 0.15 18 150 23 29
0.375 0.591 25.8 160 23.4 6
12
Mean 2sd
0.0 0.0 0.0 111 24.2 0.0
0.0 0.0 0.0 111.2 24.8 0.0
0.0 0.0 0.0 113 26.0 0.0
0.0 0.0 0.0 119 27.1 0.0
0.0 0.0 1.2 131 29.3 0.2
0.0 0.0 10.0 142 32 2.2
0.2 0.02 19 145 35.2 5.1
0.0 20.0 0.0 20.0 0.0 20.0
0.0 20.0 0.0 20.0 0.0 20.0
2.89 25.0
0.0 20.0
5.18 27.46
1.74 25.08 0.0 20.0
5.61 215.2
7.13 26.0
1.37 22.9
4.25 26.4 40.8 273.6
0.518 0.179 24.9 68.3 244.6 152 33.73 7.2
13
100 100 100 153.42 2329.4 1123.7 23875.8 0.015 20.055
100 100 100 157.33 2341.4 1129.46 23891.8 0.415 20.832
0.004 20.014 0.428 21.46 100 163.98 2343.6 1143.35 23926.7 96.05
0.028 20.08 99.11 100 173.45 2364.9 1176.78 24035.5 89.18
0.125 20.27 97.13 0.658 21.08 181.57 2372.9 1202.89 24118.6 13.33 219.2
97.35 14.45 229.7 89.57 213.87 2446.1 1239.89 24228.4 21.27 228.3
91.61 79.06 17.33 2 139 211.22 2452.7 1392.7 2 4753 39.038 2 42.8
196.0 2473.5 1496.1 2 5080 47.87 249.2
51.67 254.8 250 2 248.2
av.rem.%
21.72 23.51 99.97
19.73 23.12 99.13
16.34 22.17
99.99 99.78
11.51 19.9
99.96
99.04 7.36 18.12 72.57
99.76
ÿ107.78 15.60 55.57
92.59
74.63 ÿ107.77 5.9 18.45
Legend: (1) Fertilizer plant waste (pit 1). (2) Fertilizer plant waste (pit 2). (3) Condensate. (4) Washing ¯oor waste. (5) Acid plant waste. (6) Cooling towers waste. (7) Collection basin waste No. 1. (8) Collection basin waste No. 2. (9) Final drain. (10) Damietta. (11) Mansoura. (12) Kafr El Zayate. (13) Ed®na.
NOÿ 2 (mg/l) NOÿ 3 (mg/l) 2ÿ SO4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
168
24
NOÿ 2 (mg/l) NOÿ 3 (mg/l) 2ÿ SO4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
Cl (mg/l) COD (mg/l)
0
NOÿ 2 (mg/l) NOÿ 3 (mg/l) 2ÿ SO4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
Item/Location t, min
Table 1. Application of bacteriological treatment of wastewater by a mixture of the B. stearothermophilus Asw 88 and Asw 129
ÿ 2ÿ Bacterial removal of NOÿ 2 , NO3 and SO4
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R. M. Awadallah et al.
ÿ basin waste No. 2, (NOÿ 2 , 113; NO3 , 380 mg/l), respectively, However, COD in cooling towers waste shows 99.809% degradation. The variations of the nutrients (as individuals or in admixtures) parameters' results are aected by strains (either alone or with each other), concentrations of the nutrients (in pure salts), pollutants in wastewater and polluted Nile water and with the time applied for biological treatment. The decrease or depletion of ÿ 2ÿ nutrients' (NOÿ 2 , NO3 and SO4 ) concentrations ÿ and other contaminants or pollutants (HCOÿ 3 , Cl and COD) levels may be attributed to the biodegradation (partial or complete) eect of bacteria bioÿ ÿ 2ÿ ÿ mass on NOÿ 2 , NO3 , SO4 , Cl , HCO3 and COD. Biological eect leads to denitri®cation of NOÿ 3 into ÿ NOÿ 2 and denitroso®cation of NO2 into NH3 then NH3 into free nitrogen and consumed by nitrogen bacteria as conventional essential nutrient
2H NOÿ 3 ÿ4
NOÿ 2
4H
H2 O ÿ4 NH3 3O
H2 O, 2NH3 ÿ4 N2 3H2 O desulphurization (desalination or reduction) of SO2ÿ 4 by the eect of sulphur reducing bacteria into S2ÿ then sulphide into free sulphur and ®nally consumed as conventional essential nutrient 8H 2ÿ 2ÿ ÿ2e (SO2ÿ ÿ4 S 4H O, S ÿ4 S) and oxida2 4 ÿ O 2ÿ tion of HCOÿ 3 (2HCO3 ÿ4 CO3 H2 O CO2 ) and organic matter (COD) into C + CO2. The ÿ decrease of rate of degradation of NOÿ 2 and NO3 at higher concentrations (after 24 h) may be attributed ÿ to denitri®cation of NOÿ 3 into NO2 (Table 1). The decrease or partial degradation (removal) of Clÿ ion concentration may be ascribed to its consumption by these strains as Clÿ ion constitutes the extracellular ¯uid of microorganisms. But Clÿ ion exists in waste and polluted water at high concentration in addition to its existence in the medium (Clÿ ion is involved in the composition of medium as NaCl). This leads to an increase in the chloride ion concentration. Clÿ ion is a main constituent of extracellular ¯uid and utilized for photosynthesis and for growth of bacteria, and this is the reason for the decrease of chloride ion concentration. However, the bacterial growth rate increases with the increase ÿ ÿ 2ÿ ÿ of NOÿ 2 , NO3 , SO4 , Cl , HCO3 and COD concentrations (the concentrations of items decrease with the treatment time intervals) and is suppressed or stunted in the presence of high concentration of ÿ 2ÿ Clÿ. Finally NOÿ 2 , NO3 , SO4 and COD are completely depleted as these parameters are essential useful nutrients for these strains. By this technolÿ 2ÿ ÿ ÿ ogy, NOÿ 2 , NO3 , SO4 , HCO3 , Cl and COD can be removed or minimized.
CONCLUSION ÿ 2ÿ Based on the above results, NOÿ 2 , NO3 , SO4 , ÿ ÿ HCO3 , Cl and COD existing in industrial wastewater euents and in polluted River Nile water can ÿ 2ÿ be removed (NOÿ 2 , NO3 , SO4 and COD) or miniÿ ÿ mized (HCO3 and Cl ) by biological treatment using nitrogen and sulphur reducing bacteria and water can be utilized with safety (the applied strains are safe, i.e., nonpathogenic), for domestic, industrial and agricultural purposes. Successive treatment and careful disinfection of these waters may help for using the water in drinking (after desalination due to Clÿ) in regions suering from water problems (de®cient water resources).
REFERENCES
APHA (1980) Standard Methods for The Examination of Water and Wastewater, 15th edition. American Public Health Association, Washington, DC. Awadallah R. M. (1984) Physicochemical studies on the water samples of the High Dam Lake. Asw. Sci. Tech. Bull. Egypt 5, 77±92. Awadallah R. M. (1990) Physical and chemical properties of Aswan High Dam Lake water. Water SA 16, 79±84. Awadallah R. M., Ismail S. S., Abd El Aal M. T. and Soltan M. E. (1993) Investigation of drinking and Nile water samples of Upper Egypt. Water SA 19, 217±230. DEWAS (1980) Deutsche Einheitsverfahren zur Wasser-, Abwasser-, und Schlammuntersuchung. Verlag Chemie, Weinheim, Germany. El Dardir, M. (1984) Geochemical and sedimentological studies on the sediments of Aswan High Dam Reservoir. Ph.D. thesis, Fac. Sci. Al Azhar University Cairo, Egypt. Fritze D. J., Flossdorf E. and Claus D. (1990) Taxonomy of alkalophillic Bacillus strains. Int. J. Systematic Bacteriology 40, 92±97. Horikoshi K. and Akiba T. (1980) Alkalophillic Microorganisms, a New Microbial World. Japan Scienti®c Societies Press, Tokyo. Merck E. (1980) The Testing of Water, 5th edition. Darmstadt, Germany. Shabeb M. S. A. (1995) Isolation, identi®cation and some enzymatic activities of alkalotolerant and alkalophillic Bacteria isolated from Aswan Governorate. Assiut Sci. Bull. Assiut Univ. Egypt 24D, 216±333. Sherif M. K., Awadallah R. M. and Grass F. (1978) Rare earth elements in water samples in Lake Nasser±Lake Nubia. Assiut Sci. Bull. Assiut Univ. Egypt 7, 279±292. Sherif M. K., Awadallah R. M. and Grass F. (1980) Trace elements in water samples from Lake Nasser±Lake Nubia. J. Radioanal. Chem. 40, 267±272. Sneath P. H., Mair N. S. and Sharp E. M. (1986) Bergey's Manual of Systematic Bacteriology, Vol. 2. Williams and Wilkins, London. Soltan M. E. (1995) Eect of Kima drain wastewater on the Nile Rivers. Environmental International 21, 459± 464. Vogel A. L. (1982) A Textbook of Quantitative Inorganic Analysis, 4th edition. Wiley, New York.
Wat. Res. Vol. 32, No. 10, pp. 3080±3084, 1998 # 1998 Elsevier Science Ltd. All rights reserved Printed in Great Britain 0043-1354/98 $19.00 + 0.00
BACTERIAL REMOVAL OF NITRATE, NITRITE AND SULPHATE IN WASTEWATER R. M. AWADALLAH*, M. E. SOLTAN, M. S. A. SHABEB and S. M. N. MOALLA Department of Chemistry, Faculty of Science, Aswan, Egypt (First received May 1994; accepted in revised form February 1998) ÿ 2ÿ AbstractÐSolutions of various concentrations of NOÿ 2 , NO3 or SO4 , and equal concentrations of ÿ ÿ ÿ ÿ 2ÿ NO2 +NO3 and NO2 +NO3 +SO4 in thrice distilled water as well as in samples of industrial wastewater euents of Kima company (a factory producing ammonium nitrate coated with limestone powder fertilizer) at Aswan City and River Nile water collected from Mansoura, Damietta, Kafr El Zayat and Ed®na were tested against Bacillus Stearothermophilus Asw 88 and Bacillus Stearothermophilus Asw 129 and autoclaved at 37 and 508C for various hours using nutrient yeast extract (NYE) medium. ÿ 2ÿ Detection and assay of NOÿ 2 , NO3 and SO4 in simple salt solutions using NaNO2, NaNO3, Na2SO4 and H2SO4 after screening for 120 h indicates complete depletion of these components as they are good and convenient essential nutrient sources for both strains utilized safely for the treatment of polluted water. The strains are not pathogenic and they have no hazardous eect on human and animal life. The method is ecient and the results of the analysed water samples are consistent with the permissible safety baseline levels desired for domestic, irrigation and industrial purposes and also for drinking purposes after disinfection according to the World Health Organisation Standards. Complete depletion of ÿ ÿ ÿ SO2ÿ 4 after 96 h, NO2 and NO3 after 144 h, COD after 168 h and 23±30% degradation of Cl after 168 h, are obtained.The biological treatment of industrial wastewater euents of Kima Company and ÿ 2ÿ River Nile water at Damietta, Mansoura, Ed®na, and Kafr El Zayat containing NOÿ 2 , NO3 , SO4 , ÿ HCOÿ 3 , Cl and COD (organic matter) shows a progressive biodegradation of nutrients' levels with ÿ 2ÿ time, reaching complete depletion (NOÿ 2 , NO3 , SO4 and COD) due to the degradation eect by nitrogen and sulphur reducing bacteria. The decrease or absence (depletion) of nutrients and other parameters' levels may be related to their consumption by bacterial biomass. # 1998 Elsevier Science Ltd. All rights reserved
Key wordsÐindustrial wastewater euents, biodegradation, treatment, bacteriological, depletion, bacteria, strains, microorganisms, Kima, Company, drain INTRODUCTION
In Upper Egypt and in the Delta, many cities and industrial complexes are sited on the two banks of the River Nile in order to meet the increasing demands of water for domestic, agricultural and industrial use and for various other purposes. But some industrial establishments drain their euents directly into the River Nile, particularly those constructed on Damietta and Rosetta branches and pollute the essential source of water at Damietta, Mansoura, Kafr El Zayat and Ed®na. Many eorts and methods have been applied to treat polluted water in order to utilize the treated water in domestic use for cattle feeding and even for irrigation, because nitrite, nitrate, sulphate, organic compounds (chemical oxygen demand, COD; biochemical oxygen demand, BOD) and total hardness (TH) play a central role in the pollution of water and adversely aect the quality of water, these eects being re¯ected on biota (®sh, animal and human life). Therefore, the contribution of bacteria to the degradation of pollutants and contaminants may be *Author to whom all correspondence should be addressed.
considerable. Nevertheless the biological processes are not fully understood, and basic research is still necessary. The chemical compositions of the High Dam Lake, River Nile and Kima drain (at Aswan City, Egypt) water have been studied and characterized by many authors (Awadallah, 1984; Awadallah et al., 1993; El Dardir, 1984; Fritze et al., 1990; Sherif et al., 1978; Sneath et al., 1986). The purpose of the present work is targeted at introducing Bacillus Stearothermophilus Asw 88 and Bacillus Stearothermophilus Asw 129 as sulphur and nitrogen reducing bacterial species for the removing of ÿ 2ÿ NOÿ 2 , NO3 or SO4 as individuals or in binary and ternary admixtures in simple salts as well as applying these microorganisms for the biodegradation of ÿ 2ÿ ÿ ÿ NOÿ 3 , NO3 or SO4 , Cl , HCO3 and COD pollutants existing in industrial wastewater and in polluted Nile water.
MATERIALS AND METHODS
Chemicals All chemicals used were purchased from BDH, Aldrich, Sigma, Riedel de HaeÈn and Merck (A.R., 99.9%).
3080
ÿ 2ÿ Bacterial removal of NOÿ 2 , NO3 and SO4
Preparation of standard solutions Stock nitrite, nitrate and sulphate solutions were prepared by dissolving the appropriate amounts of NaNO2, NaNO3 and Na2SO4 and diluting with an appropriate volume of concentrated H2SO4 (A.R.,98%, sp.gr., 1.835 g/ cm3) in thrice distilled water. Appropriate dilute solutions of 1, 2, 3, 5, 10, 50, 100, 150, 200, 250 and 300 mg NOÿ 2 or NOÿ 3 /l and 5, 10, 50, 100, 200, 300, 400 and 500 mg SO2ÿ 4 /l (from Na2SO4 and H2SO4) were prepared by appropriate dilution from stock standard solutions (Merck, 1980). Isolation of microorganisms The alkalophilic strains, Bacillus Stearothermophilus Asw 88 and Bacillus Stearothermophilus Asw 129 were isolated from Aswan soil (Shabeb, 1995) and identi®ed according to recommended procedures (Sneath et al., 1986; DEWAS, 1980; Fritze et al., 1990; Horikoshi and Akiba, 1980). Preparation of the bacterial suspension (5) The original agar medium was given by Bunt and Rovira, and prepared by dissolving 0.5 g peptone, 0.3 g yeast extract and 0.5 g NaCl in 100 deionized water. The medium was sterilized at 1218C for 15 min and pH was adjusted to 10.5.
3081
was evaporated till dryness. The residue was allowed to cool, then concentrated sulphuric acid was added, followed by the addition of tridistilled water, 30% NaOH and 2.5 N NaOH. Bacterial suspension was added at the same concentration in the treated water samples. A yellow colour appeared. Absorbance of the solution was measured against a blank solution at l = 420 nm. An ÿ absorbance±concentration graph of NOÿ 2 or NO3 was constructed. In the case of the determination of sulphate, a turbidimetric method (Merck, 1980; Vogel, 1982) was applied using NaCl/HCl±glycerol±ethanol reagent and BaCl2 crystals (20±30 mesh). Transmittance (turbidity) was measured at l = 420 nm against a blank solution containing the same constituents (and bacterial suspension) except sulphate. A transmittance±concentration graph was ÿ constructed. In addition, HCOÿ in the 3 , COD and Cl industrial wastewater and in the River Nile water samples, under study, were assayed using recommended methods (APHA, 1980; Sherif et al., 1978, 1980). However, before biological treatment, Kima industrial wastewater and the surface River Nile water samples collected from Damietta, Mansoura, Kafr El Zayat and Ed®na were analysed for 2ÿ 2ÿ ÿ 2+ pH, O, free CO2, HCOÿ , Mg2+, 3 , CO3 , SO4 , OH , Ca ÿ ÿ 3ÿ , NO , NO , PO , Fe, Al, SS, DS and TH, Clÿ, SO2ÿ 4 2 3 4 COD using recommended methods (APHA, 1980; Sherif et al., 1978; Sherif et al., 1980).
Water samples collection Water samples were obtained from the washings of fertilizer tower wastes, fertilizer plant wastes (wastes No. 1 and 2), condensate basin, washing ¯oor waste, acid plant wastes basin, cooling towers basin, basin of ®nal collection (collection basins' wastes No. 1 and 2) inside the grounds of Kima Company for Chemical Industries and from the pipe of ®nal euents (®nal drain) into Kima drain shaft at Aswan, and from River Nile water at Damietta, Mansoura, Kafr El Zayat and Ed®na. The water samples were kept in ampered glass bottles. Working procedure Various concentrations of nitrite and nitrate from NaNO2 and NaNO3 (1, 2, 3, 5, 10, 50, 100, 200 mg/l), sulphate from both and Na2SO4 and H2SO4 (50, 100, 200, ÿ 300, 400, 500 mg/l), equal concentrations of NOÿ 2 +NO3 (5 + 5, 10 + 10, 50 + 50, 100 + 100, 150 + 150, 200 + 200, 250 + 250, 300 + 300 mg/l) and ÿ 2ÿ NOÿ (50 + 50 + 50, 100 + 100 + 100, 2 +NO3 +SO4 200 + 200 + 200, 300 + 300 + 300 mg/l) in 100 ml sterilized water, 100 ml of polluted water samples collected from Kima Company (washing basin of fertilizer tower wastes, condensate basin, washing ¯oor wastes basin, acid plant wastes basin, cooling towers basin, basin of ®nal collection (No. 1 and 2), 100 ml from the pipe of ®nal euents drained into Kima drain shaft and 100 ml of River Nile water taken from the surface at Damietta, Mansoura, Kafr El Zayat and Ed®na were inserted into sterilized 250 ml pyrex glass bottles and 1 ml of bacterial suspension was added to all bottles. The bottles were stoppered and incubated at 37 and 508C (the strains are facultative alkalophilic bacteria) for 24, 48, 72, 96, 120, 144 and 168 h. After incubation, the reference solutions and polluted ÿ 2ÿ water samples were analysed for NOÿ 2 , NO3 and SO4 . NOÿ 2 was determined using the modi®ed Griess±Ilosvay method (APHA, 1980). In this method, dilute sulphanilic acid and a-naphthylamine solutions were acted upon by nitrous acid, a red colouration produced which might be used for the spectrophotometric determination of nitrite against a blank (containing the same reagents and the culture media) and measuring the absorbance at l = 250 nm. NOÿ 3 was estimated applying the sodium salicylate method (DEWAS, 1980). In this method, sodium silicate was added to 50 ml of a ®ltered water sample and the solution
RESULTS AND DISCUSSION
The results of the eect of Bacillus Stearothermophilus Asw 88 and Bacillus ÿ Stearothermophilus Asw 129 on NOÿ , NO 2 3 and 2ÿ SO4 as individuals or in admixtures (binary, ÿ ÿ ÿ 2ÿ NOÿ 2 +NO3 and ternary, NO2 , NO3 +SO4 ) after biological treatment for 24, 48, 72, 96, 120, 144 and 168 h are represented in Figs 1 and 2. The results of physicochemical parameters of the water samples collected from Kima Company and Kima drain shaft at Aswan and those collected from the River Nile at Damietta, Mansoura, Ed®na and Kafr El Zayat show very high values of conductivity of Kima Company and Kima drain waters, and Nile water at Damietta. In addition, wastewaters of fertilizer plant waste pits No. 1 and 2, condensate basin and basin of washing ¯oor waste at Kima Company and Nile water at Damietta exhibit terriÿ 2+ ble ®gures of CO2ÿ , Mg2+, TH, Clÿ 3 , OH , (Ca 2ÿ ÿ and SO4 at Damietta), NO2 , NOÿ 3 , SS, DS and ÿ COD. Table 1 shows the results of NOÿ 2 , NO3 , 2ÿ ÿ ÿ SO4 , HCO3 , Cl and COD in the collected samples after biological treatment with the strains under study for 24, 48, 72, 96, 120, 144 and 168 h. The results show a progressive decrease of NOÿ 2, 2ÿ NOÿ 3 and SO4 concentrations (as individuals and in admixtures as present in pure salts) with treatÿ ment time. However, 1, 2 and 3 mg NOÿ 2 or NO3 /l are completely depleted (100% degradation) after ÿ 24 h, 5 and 10 mg NOÿ 2 or NO3 /l are completely depleted after 48 h, 50 mg NOÿ 2 /l is completely depleted after 72 h, 100 and 200 mg NOÿ 2 /l are completely depleted after 96 h, while 50, 100 and 200 mg NOÿ 2 /l are completely depleted after 120 h treatment. Mixtures of 5 + 5 and 10 + 10 and 50 + 50, 100 + 100, 150 + 150, 200 + 200,
3082
R. M. Awadallah et al.
Fig. 1. Removal of nitrite (A), nitrate (B) and sulphate (C) from a mixture of equal amounts of them by B. stearothermophilus Asw 129 and Asw 88. ÿ 250 + 250 and 300 + 300 mg/l of NOÿ 2 +NO3 are completely depleted after 48 and 120 h. Also, 50 mg SO2ÿ 4 /l (from Na2SO4 or H2SO4) are completely desin admixtures tructed after 72 h. However, SO2ÿ 4 (pure salts) are completely depleted after 48 h in the ÿ 2ÿ case of 50 mg NOÿ 2 +50 mg NO3 +50 mg SO4 (in Na2SO4 or H2SO4)/l and 120 h in the case of the other concentrations. In the polluted samples, NOÿ 2, 2ÿ NOÿ 3 and SO4 in the condensate basin (pH 10.96; NOÿ 3 , 350 mg/l) are completely depleted after 48 h. However, NOÿ 2 in washing ¯oor basin (23 mg/l), acid plant (0.15 mg/l) wastes basin, Damietta, Kafr El Zayat and Ed®na water is completely depleted after 48 h. NOÿ in collection basin No. 1, 3
Damietta, Mansoura, Kafr El Zayat and in Ed®na exhibits is completely depleted after 48 h. SO2ÿ 4 complete degradation in the condensate basin after 24 h, in washing ¯oor, acid plant, collection basins' wastes No. 1 and 2, and ®nal drain waste after 72 h and in cooling towers waste, Damietta, Mansoura, Kafr El Zayat and Ed®na after 96 h. COD has completely disappeared after 24 (condensate basin and acid plant wastes), 72 (Damietta), 96 (washing ¯oor wastes, Mansoura, Kafr El Zayat and Ed®na), 144 (collection basin No. 1, Clÿ, 103.2; SO2ÿ 4 , 85; ÿ NOÿ 2 , 117; NO3 , 360 mg/l) and 168 h (fertilizer ÿ plants' wastes No. 1 (NOÿ 2 , 110; NO3 , 530 mg/l) ÿ ÿ and 2 (NO2 , 111; NO3 , 310 mg/l) and collection
Fig. 2. Removal rates of nitrite and nitrate were almost the same irrespective of individual and in mixed solutions.
48
72
96
120
144
NOÿ 2 (mg/l) NOÿ 3 (mg/l) SO2ÿ 4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
NOÿ 2 (mg/l) NOÿ 3 (mg/l) SO2ÿ 4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
NOÿ 2 (mg/l) NOÿ 3 (mg/l) SO2ÿ 4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
NOÿ 2 (mg/l) NOÿ 3 (mg/l) SO2ÿ 4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
NOÿ 2 (mg/l) NOÿ 3 (mg/l) 2ÿ SO4 (mg/l) HCOÿ 3 (mg/l) ÿ
0.0 0.0 0.0 35.1 25.9 0.0
0.0 0.0 0.0 38.2 27.3 1.2
0.0 0.03 0.0 42.1 28.7 7.2
0.0 0.12 0.0 44.1 29.9 13.1
0.15 2.1 2.3 48.2 31.2 25.2
1.68 9.87 6.82 51.9 34.8 33.2
5.5 17.75 17.35 60 36.6 57.3
110 530 82 0.0 46.45 75.6
1
0.0 0.0 0.0 28.1 29.0 0.0
0.0 0.0 0.0 28.4 29.2 0.7
0.05 0.12 0.0 29.6 30.5 3.4
0.23 0.88 0.0 32.6 31.2 6.5
0.45 2.3 0.13 5.2 5.2 14.0
10.2 11.02 4.9 53.2 36.4 29.6
17.25 20.75 12.25 62 39.2 42.4
111 310 78 0.0 54.19 68
2
0.0 0.0 0.0 27.7 169 0.0
0.0 0.0 0.0 27.9 172 0.0
0.0 0.0 0.0 29.0 189 0.0
0.0 0.0 0.0 31.0 195 0.0
0.0 0.0 0.0 35 200.1 0.0
0.0 0.0 0.0 38 225 0.0
1.4 202.2 0.0 40 250 0.0
0.3 330 0.0 0.0 309.7 2.8
3
0.0 0.0 0.0 30.9 12.9 0.0
0.0 0.0 0.0 31.0 13.8 0.0
0.0 5.3 0.0 31.2 14.3 0.0
0.0 18.4 0.0 33.1 15.9 0.0
0.0 55.3 0.0 36 16.2 0.6
0.0 110 4.51 42.0 18.3 5.2
1.9 205 9.72 46 21.5 14.9
23 800 61 0.0 33.55 18.4
4
0.0 0.0 0.0 99.5 13.5 0.0
0.0 0.0 0.0 99.8 14.2 0.0
0.0 0.0 0.0 102 15.1 0.0
0.0 0.0 0.0 109 16.2 0.0
0.0 0.0 0.0 118 17.3 0.0
0.0 20 3.92 145.0 19.8 0.0
0.08 0.0 8.61 49.7 24.9 0.0
0.15 5.0 52 168 30.97 18.4
5
0.0 0.0 0.0 100.4 20.4 0.2
0.0 0.0 0.0 101 21.2 2.9
0.0 0.12 0.0 105 23.9 12.1
0.0 3.1 0.0 111 25.1 23.6
0.0 9.3 0.1 122 29.2 65.1
0.05 22.2 5.61 152.0 33.2 98
1.2 45.5 16.65 161.3 37.9 147
(A) 78 335 99 168 41.29 162.8
6
8
9
At 0 h (before treatment) 117 119 109 360 380 200 85 93 90 0.0 0.0 0.0 103.2 206.5 141.9 74.4 90 86.8 (B) After 24 h 4.05 4.5 18.75 2.25 11.22 25.75 13.1 15.85 14.78 90.6 47.9 43.4 89.6 187.5 126.3 59.7 74.9 69.8 (C) After 48 h 0.92 1.10 3.7 0.0 5.4 9.2 5.3 4.81 4.21 89.0 45.2 43.0 75.3 178.3 117.3 4.2 35.4 45.2 (D) After 72 h 0.05 0.15 0.32 0.0 1.2 2.7 0.0 0.0 0.0 82 41 39 68.9 159.4 110.2 13.2 25.6 29.1 (E) After 96 h 0.0 0.0 0.05 0.0 0.06 0.12 0.0 0.0 0.0 79.0 37.0 36.0 61.1 149.2 103 2.5 9.2 12.5 (F) After 120 h 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 77 36 34.9 59.4 139.2 98.2 0.5 1.4 0.0 (G) After 144 h 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 58.3 38.1 97.5 49.5 129.2 95.4 0.0 0.2 0.4 (H) After 168 h 0.0 0.0 0.0 0.0 0.0 0.0 0.0 .0 0.0 58.0 37.8 97.2 47.2 126.5 93.3 0.0 0.0 0.0
7
11
0.0 0.0 0.0 12.8 11.2 0.0
0.0 0.0 0.0 12.9 11.5 0.0
0.0 0.0 0.0 115 13.1 0.0
0.0 0.0 0.0 121 15.3 0.0
0.0 0.0 0.35 125 16.4 0.0
0.0 0.0 7.55 139.0 18.2 0.2
0.16 0.02 20 140 23.9 2.1
0.0 0.0 0.0 1243 14022 0.0
0.0 0.0 0.0 1287 14081 0.0
0.0 0.0 0.0 1301 14211 0.0
0.0 0.0 0.0 1381 14613 0.0
0.0 0.0 3.4 1415 14909 0.2
0.05 0.0 25.1 1690 15311 2.1
0.12 0.0 60 1710 17210 5.3
0.212 3.18 0.172 0.022 25.1 172 150 1750 23.4 18401 3.6 8.3
10
0.0 0.0 0.0 113 13.1 0.0
0.0 0.0 0.0 114 13.9 0.0
0.0 0.0 0.0 116 15.1 0.0
0.0 0.0 0.0 121 16.2 0.0
0.0 0.0 1.1 133 17.2 0.1
0.0 0.0 9.9 150 19 1.2
0.19 0.15 18 150 23 29
0.375 0.591 25.8 160 23.4 6
12
Mean 2sd
0.0 0.0 0.0 111 24.2 0.0
0.0 0.0 0.0 111.2 24.8 0.0
0.0 0.0 0.0 113 26.0 0.0
0.0 0.0 0.0 119 27.1 0.0
0.0 0.0 1.2 131 29.3 0.2
0.0 0.0 10.0 142 32 2.2
0.2 0.02 19 145 35.2 5.1
0.0 20.0 0.0 20.0 0.0 20.0
0.0 20.0 0.0 20.0 0.0 20.0
2.89 25.0
0.0 20.0
5.18 27.46
1.74 25.08 0.0 20.0
5.61 215.2
7.13 26.0
1.37 22.9
4.25 26.4 40.8 273.6
0.518 0.179 24.9 68.3 244.6 152 33.73 7.2
13
100 100 100 153.42 2329.4 1123.7 23875.8 0.015 20.055
100 100 100 157.33 2341.4 1129.46 23891.8 0.415 20.832
0.004 20.014 0.428 21.46 100 163.98 2343.6 1143.35 23926.7 96.05
0.028 20.08 99.11 100 173.45 2364.9 1176.78 24035.5 89.18
0.125 20.27 97.13 0.658 21.08 181.57 2372.9 1202.89 24118.6 13.33 219.2
97.35 14.45 229.7 89.57 213.87 2446.1 1239.89 24228.4 21.27 228.3
91.61 79.06 17.33 2 139 211.22 2452.7 1392.7 2 4753 39.038 2 42.8
196.0 2473.5 1496.1 2 5080 47.87 249.2
51.67 254.8 250 2 248.2
av.rem.%
21.72 23.51 99.97
19.73 23.12 99.13
16.34 22.17
99.99 99.78
11.51 19.9
99.96
99.04 7.36 18.12 72.57
99.76
ÿ107.78 15.60 55.57
92.59
74.63 ÿ107.77 5.9 18.45
Legend: (1) Fertilizer plant waste (pit 1). (2) Fertilizer plant waste (pit 2). (3) Condensate. (4) Washing ¯oor waste. (5) Acid plant waste. (6) Cooling towers waste. (7) Collection basin waste No. 1. (8) Collection basin waste No. 2. (9) Final drain. (10) Damietta. (11) Mansoura. (12) Kafr El Zayate. (13) Ed®na.
NOÿ 2 (mg/l) NOÿ 3 (mg/l) 2ÿ SO4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
168
24
NOÿ 2 (mg/l) NOÿ 3 (mg/l) 2ÿ SO4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
Cl (mg/l) COD (mg/l)
0
NOÿ 2 (mg/l) NOÿ 3 (mg/l) 2ÿ SO4 (mg/l) HCOÿ 3 (mg/l) Clÿ (mg/l) COD (mg/l)
Item/Location t, min
Table 1. Application of bacteriological treatment of wastewater by a mixture of the B. stearothermophilus Asw 88 and Asw 129
ÿ 2ÿ Bacterial removal of NOÿ 2 , NO3 and SO4
3083
3084
R. M. Awadallah et al.
ÿ basin waste No. 2, (NOÿ 2 , 113; NO3 , 380 mg/l), respectively, However, COD in cooling towers waste shows 99.809% degradation. The variations of the nutrients (as individuals or in admixtures) parameters' results are aected by strains (either alone or with each other), concentrations of the nutrients (in pure salts), pollutants in wastewater and polluted Nile water and with the time applied for biological treatment. The decrease or depletion of ÿ 2ÿ nutrients' (NOÿ 2 , NO3 and SO4 ) concentrations ÿ and other contaminants or pollutants (HCOÿ 3 , Cl and COD) levels may be attributed to the biodegradation (partial or complete) eect of bacteria bioÿ ÿ 2ÿ ÿ mass on NOÿ 2 , NO3 , SO4 , Cl , HCO3 and COD. Biological eect leads to denitri®cation of NOÿ 3 into ÿ NOÿ 2 and denitroso®cation of NO2 into NH3 then NH3 into free nitrogen and consumed by nitrogen bacteria as conventional essential nutrient
2H NOÿ 3 ÿ4
NOÿ 2
4H
H2 O ÿ4 NH3 3O
H2 O, 2NH3 ÿ4 N2 3H2 O desulphurization (desalination or reduction) of SO2ÿ 4 by the eect of sulphur reducing bacteria into S2ÿ then sulphide into free sulphur and ®nally consumed as conventional essential nutrient 8H 2ÿ 2ÿ ÿ2e (SO2ÿ ÿ4 S 4H O, S ÿ4 S) and oxida2 4 ÿ O 2ÿ tion of HCOÿ 3 (2HCO3 ÿ4 CO3 H2 O CO2 ) and organic matter (COD) into C + CO2. The ÿ decrease of rate of degradation of NOÿ 2 and NO3 at higher concentrations (after 24 h) may be attributed ÿ to denitri®cation of NOÿ 3 into NO2 (Table 1). The decrease or partial degradation (removal) of Clÿ ion concentration may be ascribed to its consumption by these strains as Clÿ ion constitutes the extracellular ¯uid of microorganisms. But Clÿ ion exists in waste and polluted water at high concentration in addition to its existence in the medium (Clÿ ion is involved in the composition of medium as NaCl). This leads to an increase in the chloride ion concentration. Clÿ ion is a main constituent of extracellular ¯uid and utilized for photosynthesis and for growth of bacteria, and this is the reason for the decrease of chloride ion concentration. However, the bacterial growth rate increases with the increase ÿ ÿ 2ÿ ÿ of NOÿ 2 , NO3 , SO4 , Cl , HCO3 and COD concentrations (the concentrations of items decrease with the treatment time intervals) and is suppressed or stunted in the presence of high concentration of ÿ 2ÿ Clÿ. Finally NOÿ 2 , NO3 , SO4 and COD are completely depleted as these parameters are essential useful nutrients for these strains. By this technolÿ 2ÿ ÿ ÿ ogy, NOÿ 2 , NO3 , SO4 , HCO3 , Cl and COD can be removed or minimized.
CONCLUSION ÿ 2ÿ Based on the above results, NOÿ 2 , NO3 , SO4 , ÿ ÿ HCO3 , Cl and COD existing in industrial wastewater euents and in polluted River Nile water can ÿ 2ÿ be removed (NOÿ 2 , NO3 , SO4 and COD) or miniÿ ÿ mized (HCO3 and Cl ) by biological treatment using nitrogen and sulphur reducing bacteria and water can be utilized with safety (the applied strains are safe, i.e., nonpathogenic), for domestic, industrial and agricultural purposes. Successive treatment and careful disinfection of these waters may help for using the water in drinking (after desalination due to Clÿ) in regions suering from water problems (de®cient water resources).
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